Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Sensors are often used to detect and measure waves and disturbances manifest in a particular form of energy. Some sensing devices include electronic components for facilitating the recording of information representative of measurements captured by the sensing device. For example, a sensing device might include an analog-to-digital converter (ADC) for converting analog measurements to digital data. Operation of a ADC typically involves sampling analog measurements against a clock in order to quantize analog measurements to form discrete-time signal data. The clock may server as a reference to which data recorded by one sensor may be synchronized against another reference.
In practice, clock devices are susceptible to clock drift—instabilities in the clock's frequency that causes it to deviate from an intended frequency—resulting from differences in design, manufacturing imperfections, and environmental conditions. In some sensor networks, each sensing device might include its own separate clock, each of which can drift with respect to the other clocks in the network. As the clocks in such a network drift, the time values assigned to data recorded by the sensors becomes increasingly out of phase. Therefore, the integrity of timing-sensitive data may be adversely affected in sensor networks with out-of-sync clocks. Such imprecision may be undesirable in circumstances where the relative timing of events measured across multiple sensors is of interest.